Bugfix: Fix soil advice multi-turn conversation logic to prevent session hijacking

Feature: Integrated Prophet-based Profit/Loss forecasting for crop recommendations

Security: Refactor to map API keys and sensitive tokens to environment variables using dotenv

UI Tweaks: Move Guide button to header next to theme toggle

UI Tweaks: Remove Neural Engine text and fix button cutoff

Fix active session override bug and feature array inflation

Fix AdaBoost 10 features error, enforce 4 elements length restriction in data store, and fix order of PH in model inference array.

Initial commit with LFS